Icterus – see jaundice.
Impetigo – Contagious skin disease charac terized by pustules.
Inanition – Exhaustion from lack of nourishment; starvation. A condition characterized by marked weakness, extreme weight loss, and a decrease in metabolism resulting from severe and prolonged (usually weeks to months) insufficiency of food.
Infantile paralysis – Polio.
Infection – The affection or contamination of a person, organ, or wound with invading, multiplying, disease-producing germs (such as bacteria, rickettsiae, viruses, molds, yeasts, and protozoa). In the early part of the last century, infections were thought to be the propagation of disease by effluvia (see above) from patients crowded together. “Miasms” were believed to be substances which could not be seen in any form, emanations not apparent to the senses. Such miasms were understood to act by infection.
Inflammation – Redness, swelling, pain, tenderness, heat, and disturbed function of an area of the body, especially as a reaction of tissue to injurious agents. This mechanism serves as a localized and protective response to injury. The word ending -itis denotes inflammation on the part indicated by the word stem to which it is attached, as in: appendicitis, pleuritis, etc. Microscopically, it involves a complex series of events, including enlargement of the sizes of blood vessels; discharge of fluids, including plasma proteins; and migration of leukocytes (white blood cells) into the inflammatory focus. In the last century, cause of death often was listed as inflammation of a body organ, such as brain or lung, but this was purely a descriptive term and is not helpful in identifying the actual underlying disease.
Intestinal colic – Abdominal pain due to bad or improper diet.
Intussusception – The slipping of one part within another, as the prolapse of one part of the intestine into the lumen of an immediately adjoining part. This leads to obstruction and often must be relieved by surgery. Synonym: introsusception.
